Network layer packet structure

Abstract

A packet switching communication system is improved by using a packet header structure which does not require a fixed format. The packet header comprises a chain of 2 byte command/data segments. Each command/data segment contains generic bits and a routing field. One of the generic bits (bit 1) allows the header to be extended with another command/data segment.

We claim: 
     
       1. For use in a fast packet switching network used for transporting digital data packets, each packet having a header structure which includes a plurality of command and data segments, each with a disable indicator and one or more control bits, said network having a plurality of switching nodes interconnected by transmission links, a method of processing packets, said method being implemented at one or more of the switching nodes and including the steps of: receiving packets from other switching nodes over the transmission links;   detecting the state of the disable indicator in each of the command and data segments in the header structure of each received packet;   passing over any command and data segment having a disable indicator having a predetermined first value; and   performing predetermined operations on the packet in accordance with the control bits found in the first command and data segment encountered having a disable indicator having a predetermined second value.   
     
     
       2. A method as set forth in claim 1 further including the step of setting, to the predetermined first value, the disable indicator in a command and data sequence which has been used in controlling the performance of packet operations. 
     
     
       3. In a fast packet switching network to be used for transporting digital data packets, each packet having a header structure which includes a plurality of command and data segments, each with a disable indicator and one or more control bits, said network having a plurality of switching nodes interconnected by transmission links, each switching node including: means for receiving packets from other switching nodes over the transmission links;   means for detecting the state of the disable indicator in each of the command and data segments in the header structure of each received packet;   means for passing over any command and data segment having a disable indicator having a predetermined first value; and   means for performing predetermined operations on the packet in accordance with the control bits found in the first command and data segment encountered having a disable indicator having a predetermined second value.   
     
     
       4. A switching node as set forth in claim 3 further including means for setting, to the predetermined first value, the disable indicator in a command and data sequence which has been used in controlling the performance of packet operations.